The present invention relates to a push-button switch.
In a prior-art switch, a base plate formed from a phenol-resin lamination or the like has holes formed by punching for receiving terminals, and fixed terminals are inserted in these holes and then fixed by caulking. With this structure, when the automatic soldering is performed to connect the terminals in a circuit, a flux from the solder sometimes spreads along the fixed terminal and flows into the switch through a gap between the terminal and its hole in the base plate. Such gaps are, therefore, often filled to prevent penetration of the flux by a coating of a binder. However, coating with binder is very laborious. For this reason, it is recent practice to fabricate a switch case by molding a synthetic resin and embedding the fixed terminals during the molding process. In general, however, when a box-shaped switch case is made by plastic molding, the upper edges on the open side may bend inwards to some extent, and this inevitably leads to serious problems. It is also the present state of the art that a very high precision cannot always be expected in molding a synthetic resin. With such switch case made by plastic molding, the presence of the aforecited deformation sometimes leads to the disadvantage that a slide member cannot be inserted into the switch case or that the movement of the slide member is not smooth. Conversely, when a dimensional allowance is made great, the play of the slide member increases, which can result in the disadvantage that the switch does not execute a smooth operation in the changes of state of the switch.
In assembling a push-button switch which employs a heart-shaped cam groove to contact operation, a lock pin needs to be accurately positioned in the heart-shaped cam groove and to be normally urged therein by a leaf spring or the like. In addition, since respective components are often small, the assemblage must inevitably be performed by hand. These become serious problems in permitting assemblage of the switch by automation.